Accumulation

B) increasing (3.25, 8)  decreasing (0, 3.25)

C) maximum at x = 8 - value is 3.5 + π/2
      minimum at x = 3.25 - value is -3.625

D) concave up (2, 3) (4, 5) (6, 7)
     concave down (1, 2) (3, 4) (5, 6) (7, 8)